Head bolt broken and stuck
i broke a torx bit off in mine (a small one - use a big one - bigger than a 1/4"), and you cant dril through tool steel.
LS1 head bolt threads are very odd. there is no tap commonly available. dont waiste your time looking. kent moore is the only one who makes it, and the kit costs $350.
you need to find a shop that can do "EDM". what that is - they burn out the bolt w/ an electrical arc. they can burn a shape into the end (like an allen) but w/ mine being 3" down in the hole they couldnt do it. they just melted out the torx for me. i went home and broke a bolt exstractor off in it in 5 minutes of getting home from the EDM shop. drill a 1/4" hole all the way thru the bolt before you try to back it out w/ anything. this way if you break something else off in it, you can pound it out thru the other side.
now for the bad news - no EDM shop / machine shop would try to EDM/bore out the bolt w/ the oilpan or crank in the motor. muchless the motor in the car. what started off as an $1800 head upgrade, turned into a $7000 motor rebuild - do it while it's out i always say.
PM or email me if you wanna talk more about this. Glenn_Landrum@msn.com



